1. Field of the Invention
The present invention relates to an organic light emitting display. More particularly, the present invention relates to an organic light emitting display having excellent stability.
2. Description of the Related Art
Recently, display panels using an organic light emitting display are in the spotlight, and semiconductor techniques for manufacturing these displays are rapidly being developed.
Organic light emitting displays generally include a panel assembly with organic light emitting diodes, a bezel connected to the panel assembly at the rear part thereof, and a printed circuit substrate electrically connected to the panel assembly through a flexible printed circuit (FPC).
The panel assembly of the organic light emitting display is formed of two very thin substrates that have an empty space therebetween. In addition, an anode electrode and a cathode electrode are formed on the substrates. The cathode is formed with a material having a low work function, for example a highly reactive alloy including an alkali metal and an alkaline earth metal. The reactive metal oxidizes easily by reacting with oxygen or moisture, resulting in the deterioration of device characteristics or the shortening of device life-span. In addition, an organic material layer formed below the cathode layer is susceptible to rapid deterioration from exposure to oxygen and moisture.
Accordingly, the organic light emitting display has an encapsulation structure in which a glass or metal cap is adhered to the top thereof through interposing a sealant between it and the anode electrode. A moisture absorbent getter is adhered to the bottom part of the cap with adhesive tape, and the getter captures moisture flowing from the outside through the adhesive part to maintain the device in a stable state.
Instead of a metal or glass cap, an organic light emitting display may be encapsulated by two or more organic and/or inorganic layers that are layered together, with a print material fused with a laser, or with an encapsulation layer that is formed by dispersing a moisture absorbent in a polymer. Researches for determining new and better ways to encapsulate organic light emitting displays are ongoing.